NASHVILLE — The U.S. Department of Agriculture announced changes to the Horse Protection Act on Friday that many hailed as a major step toward ending the abusive practice of “soring.”

Soring is the practice of intentionally abusing Tennessee walking horses and related breeds to exaggerate their gait, causing the animals pain each time they step so they lift their front legs higher in what is known as the "big lick." The abuse often includes the use of caustic chemicals cooked into the skin and then irritated by chains, but also can involve shoving objects between the hoof and stacked shoes, among other methods.

The new rule will ban much of the gear used, including chains placed around horses' ankles during training and stacks — the tall weights attached to the front hooves.

It also will force inspectors to become trained and licensed through the USDA's Animal and Plant Health Inspection Service.

"(The USDA is) taking away the most obvious and ubiquitous tools used for soring," said Keith Dane, senior adviser on equine protection for the Humane Society of the United States. "We’re very encouraged by the rule."

Humane Society President Wayne Pacelle said reformers have devoted countless hours to help outlaw "a practice that is as deplorable and intentional as dogfighting or cockfighting."

The horse industry is currently responsible for training its own inspectors in what the USDA says is a conflict of interest that leaves them with no incentive to find violations. During audits, federal inspectors consistently find more sored horses than private inspectors do.

The new trainers would be veterinarians and veterinarian educators. The USDA said it will be able to deny an application for a horse protection inspector's license or revoke the license of an inspector "who does not meet the minimum requirements, who fails to follow the designated inspection procedures, or who otherwise fails to carry out his or her duties and responsibilities in a satisfactory manner."

In one alteration of the initial proposal, the USDA will not tighten regulations on heavy horse shoes or the metal bands strapped across hooves. Dane said it could lead to problems because the bands are sometimes tightened to induce pain or used to cover abuse to the tops of the horses' hooves.

A pastern of walking horse Skywalks Magical Dream is shown with open wounds and scars.(Photo: Provided by Horse Plus Humane Society)

The announcement came after more than 200 legislators and several activists placed bipartisan pressure on the Obama administration to strengthen protections against soring before President-elect Donald Trump takes office.

But not everyone welcomed the decision.

Mike Inman, president of the Tennessee Walking Horse National Celebration, said he plans to challenge the regulatory action. The group, based in Shelbyville, Tenn., is the largest Tennessee walking horse show in the nation.

"The avenues available are, of course, to file a legal challenge, and we are prepared to do that," Inman said.

He said a Trump administration could put the rule changes on hold until they can be reviewed.

"During that review time, our industry would look forward to presenting the facts that we feel would lead to a different course of action," he said.

Dane said the Humane Society is expecting industry supporters to challenge the decision but that it is prepared to work with the USDA to fight back.

In this 2014 file photo, activists staged a rally in front of the U.S. Capitol to raise public awareness of the abusive horse-training method known as soring.(Photo: Jack Gruber, USA TODAY)

Dane and others recommended that show owners focus instead on promoting flatshod competitors, or horses that are not made to wear action devices, saying they already possess a naturally attractive gait.

"They can focus back on the true beauty and not make it artificially," said Tawnee Preisner, founder of Horse Plus Humane Society. "It’s going to take a lot of stigma away from Tennessee."

Walking horse owners Sammy and Gayle Cagle, the former owners of one illegally sored horse Preisner rescued from an auction last year, warned during the USDA's comment period that their show horses would lose their value if the USDA were to ban stacks and chains, saying, "The slaughter trailers are waiting."

Preisner said Horse Plus Humane Society is working to prepare for the possible influx of walking horses being dumped at auction.

"We will take any Tennessee walking horse that owners cannot keep now due to this new law," she said. "If they really love them, they won't dump them into the slaughter pipeline."

Sored horses often end up at low-end auctions once signs of the abuse become too obvious to pass inspection or when young horses are resistant to abusive training.